370 1d ds 
ALLEN. 
animal will be white, though it may still retain the power of transmitting 
a particular colour to its offspring. 
The black or brown factor is present 
in the animal’s constitution, but in the absence of the colour factor the 
black or brown does not appear. 
Purr BLACK 
Pure RED 
BLACK carryvinc RED (Hyprip BLACK). cal 
CB 
CB 
ALBINO cARRYING BLACK : : : |: zl 
cB 
- ALBINO cARRYING RED 
ALBINO cARRYING BLACK AND RED cB 
cR 
BLACK CARRYING ALBINO : ; f CB 
cB 
RED CARRYING ALBINO CR 
cR 
BLACK cARRYING RED AND ALBINO CB 
cR 
BLACK NO-WHITE wCB 
wCB 
RED NO-WHITE wCR 
wCR 
DIAGRAM &. 
Kye-colour of Gammarus. Constitutions of some of the different kinds. 
C represents the factor for colour, ¢ the absence of this factor. 
B represents the factor for black, R that for red. 
w represents the factor for absence of white pigment. 
Animals of the first nine constitutions shown on the diagram all possess the white 
pigment, and this might have been indicated by adding W to the formula in 
each case. 
A similar hypothesis will explain the present case. Diagram 8 shows 
the constitutions on this hypothesis of some of the varieties of Gammarus 
